internal void VerifyIDBCreateCommand(OleDbConnectionString constr)
{
// DangerousAddRef/DangerousRelease are not neccessary here in the current implementation
// only used from within OleDbConnectionInternal.ctor->DataSourceWrapper.InitializeAndCreateSession
Debug.Assert(constr.HaveQueriedForCreateCommand, "expected HaveQueriedForCreateCommand");
Debug.Assert(null != constr.DangerousIDBCreateCommandCreateCommand, "expected DangerousIDBCreateCommandCreateCommand");
// native COM rules are the QI result is the 'this' pointer
// the pointer stored at that location is the vtable
// since IDBCreateCommand is a public,shipped COM interface, its layout will not change (ever)
IntPtr vtable = Marshal.ReadIntPtr(base.handle, 0);
IntPtr method = Marshal.ReadIntPtr(vtable, 3 * IntPtr.Size);
// obtain the cached delegate to be cached on this instance
UnsafeNativeMethods.IDBCreateCommandCreateCommand CreateCommand = constr.DangerousIDBCreateCommandCreateCommand;
// since the delegate lifetime is longer than the original instance used to create it
// we double check before each usage to verify the delegates function pointer
if ((null == CreateCommand) || (method != Marshal.GetFunctionPointerForDelegate(CreateCommand)))
{
CreateCommand = (UnsafeNativeMethods.IDBCreateCommandCreateCommand)Marshal.GetDelegateForFunctionPointer(method, typeof(UnsafeNativeMethods.IDBCreateCommandCreateCommand));
constr.DangerousIDBCreateCommandCreateCommand = CreateCommand;
}
// since this instance can be used to create multiple commands
// cache it on the class so that the function pointer doesn't have to be validated every time
DangerousIDBCreateCommandCreateCommand = CreateCommand;
}
internal void QueryInterfaceIDBCreateCommand(OleDbConnectionString constr)
{
if (!constr.HaveQueriedForCreateCommand || (constr.DangerousIDBCreateCommandCreateCommand != null))
{
IntPtr zero = IntPtr.Zero;
RuntimeHelpers.PrepareConstrainedRegions();
try
{
UnsafeNativeMethods.IUnknownQueryInterface delegateForFunctionPointer = (UnsafeNativeMethods.IUnknownQueryInterface) Marshal.GetDelegateForFunctionPointer(Marshal.ReadIntPtr(Marshal.ReadIntPtr(base.handle, 0), 0), typeof(UnsafeNativeMethods.IUnknownQueryInterface));
int num = delegateForFunctionPointer(base.handle, ref ODB.IID_IDBCreateCommand, ref zero);
if ((0 <= num) && (IntPtr.Zero != zero))
{
IntPtr ptr = Marshal.ReadIntPtr(Marshal.ReadIntPtr(zero, 0), 3 * IntPtr.Size);
this.DangerousIDBCreateCommandCreateCommand = (UnsafeNativeMethods.IDBCreateCommandCreateCommand) Marshal.GetDelegateForFunctionPointer(ptr, typeof(UnsafeNativeMethods.IDBCreateCommandCreateCommand));
constr.DangerousIDBCreateCommandCreateCommand = this.DangerousIDBCreateCommandCreateCommand;
}
constr.HaveQueriedForCreateCommand = true;
}
finally
{
if (IntPtr.Zero != zero)
{
IntPtr handle = base.handle;
base.handle = zero;
Marshal.Release(handle);
}
}
}
}
internal OleDbHResult CreateCommand(ref object icommandText)
{
// if (null == CreateCommand), the IDBCreateCommand isn't supported - aka E_NOINTERFACE
OleDbHResult hr = OleDbHResult.E_NOINTERFACE;
UnsafeNativeMethods.IDBCreateCommandCreateCommand CreateCommand = DangerousIDBCreateCommandCreateCommand;
if (null != CreateCommand)
{
bool mustRelease = false;
RuntimeHelpers.PrepareConstrainedRegions();
try {
DangerousAddRef(ref mustRelease);
// call IDBCreateCommand::CreateCommand via the delegate directly for IDBCreateCommand
hr = CreateCommand(base.handle, IntPtr.Zero, ref ODB.IID_ICommandText, ref icommandText);
}
finally {
if (mustRelease)
{
DangerousRelease();
}
}
}
return(hr);
}
internal void QueryInterfaceIDBCreateCommand(OleDbConnectionString constr)
{
if (!constr.HaveQueriedForCreateCommand || (constr.DangerousIDBCreateCommandCreateCommand != null))
{
IntPtr zero = IntPtr.Zero;
RuntimeHelpers.PrepareConstrainedRegions();
try
{
UnsafeNativeMethods.IUnknownQueryInterface delegateForFunctionPointer = (UnsafeNativeMethods.IUnknownQueryInterface)Marshal.GetDelegateForFunctionPointer(Marshal.ReadIntPtr(Marshal.ReadIntPtr(base.handle, 0), 0), typeof(UnsafeNativeMethods.IUnknownQueryInterface));
int num = delegateForFunctionPointer(base.handle, ref ODB.IID_IDBCreateCommand, ref zero);
if ((0 <= num) && (IntPtr.Zero != zero))
{
IntPtr ptr = Marshal.ReadIntPtr(Marshal.ReadIntPtr(zero, 0), 3 * IntPtr.Size);
this.DangerousIDBCreateCommandCreateCommand = (UnsafeNativeMethods.IDBCreateCommandCreateCommand)Marshal.GetDelegateForFunctionPointer(ptr, typeof(UnsafeNativeMethods.IDBCreateCommandCreateCommand));
constr.DangerousIDBCreateCommandCreateCommand = this.DangerousIDBCreateCommandCreateCommand;
}
constr.HaveQueriedForCreateCommand = true;
}
finally
{
if (IntPtr.Zero != zero)
{
IntPtr handle = base.handle;
base.handle = zero;
Marshal.Release(handle);
}
}
}
}
// if OleDbConnectionString.DangerousIDBCreateCommandCreateCommand does not exist
// this method will be called to query for IDBCreateCommand (and cache that interface pointer)
// or it will be known that IDBCreateCommand is not supported
internal void QueryInterfaceIDBCreateCommand(OleDbConnectionString constr)
{
// DangerousAddRef/DangerousRelease are not neccessary here in the current implementation
// only used from within OleDbConnectionInternal.ctor->DataSourceWrapper.InitializeAndCreateSession
// caching the fact if we have queried for IDBCreateCommand or not
// the command object is not supported by all providers, they would use IOpenRowset
// added extra if condition
// If constr.HaveQueriedForCreateCommand is false, this is the first time through this method and we need to set up the cache for sure.
// If two threads try to set the cache at the same time, everything should be okay. There can be multiple delegates that point to the same unmanaged function.
// If constr.HaveQueriedForCreateCommand is true, we have already tried to query for IDBCreateCommand on a previous call to this method, but based on that alone,
// we don't know if another thread set the flag, or if the provider really doesn't support commands.
// If constr.HaveQueriedForCreateCommand is true and constr.DangerousIDBCreateCommandCreateCommand is not null, that means that another thread has set it after we
// determined we needed to call QueryInterfaceIDBCreateCommand -- otherwise we would have called VerifyIDBCreateCommand instead
// In that case, we still need to set our local DangerousIDBCreateCommandCreateCommand, so we want to go through the if block even though the cache has been set on constr already
if (!constr.HaveQueriedForCreateCommand || (null != constr.DangerousIDBCreateCommandCreateCommand))
{
IntPtr idbCreateCommand = IntPtr.Zero;
RuntimeHelpers.PrepareConstrainedRegions();
try
{
// native COM rules are the QI result is the 'this' pointer
// the pointer stored at that location is the vtable
// since IUnknown is a public,shipped COM interface, its layout will not change (ever)
IntPtr vtable = Marshal.ReadIntPtr(base.handle, 0);
IntPtr method = Marshal.ReadIntPtr(vtable, 0);
UnsafeNativeMethods.IUnknownQueryInterface QueryInterface = (UnsafeNativeMethods.IUnknownQueryInterface)Marshal.GetDelegateForFunctionPointer(method, typeof(UnsafeNativeMethods.IUnknownQueryInterface));
int hresult = QueryInterface(base.handle, ref ODB.IID_IDBCreateCommand, ref idbCreateCommand);
if ((0 <= hresult) && (IntPtr.Zero != idbCreateCommand))
{
vtable = Marshal.ReadIntPtr(idbCreateCommand, 0);
method = Marshal.ReadIntPtr(vtable, 3 * IntPtr.Size);
DangerousIDBCreateCommandCreateCommand = (UnsafeNativeMethods.IDBCreateCommandCreateCommand)Marshal.GetDelegateForFunctionPointer(method, typeof(UnsafeNativeMethods.IDBCreateCommandCreateCommand));
constr.DangerousIDBCreateCommandCreateCommand = DangerousIDBCreateCommandCreateCommand;
}
// caching the fact that we have queried for IDBCreateCommand
constr.HaveQueriedForCreateCommand = true;
}
finally
{
if (IntPtr.Zero != idbCreateCommand)
{
IntPtr ptr = base.handle;
base.handle = idbCreateCommand;
Marshal.Release(ptr);
}
}
}
//else if constr.HaveQueriedForCreateCommand is true and constr.DangerousIDBCreateCommandCreateCommand is still null, it means that this provider doesn't support commands
}
internal void VerifyIDBCreateCommand(OleDbConnectionString constr)
{
IntPtr ptr = Marshal.ReadIntPtr(Marshal.ReadIntPtr(base.handle, 0), 3 * IntPtr.Size);
UnsafeNativeMethods.IDBCreateCommandCreateCommand dangerousIDBCreateCommandCreateCommand = constr.DangerousIDBCreateCommandCreateCommand;
if ((dangerousIDBCreateCommandCreateCommand == null) || (ptr != Marshal.GetFunctionPointerForDelegate(dangerousIDBCreateCommandCreateCommand)))
{
dangerousIDBCreateCommandCreateCommand = (UnsafeNativeMethods.IDBCreateCommandCreateCommand)Marshal.GetDelegateForFunctionPointer(ptr, typeof(UnsafeNativeMethods.IDBCreateCommandCreateCommand));
constr.DangerousIDBCreateCommandCreateCommand = dangerousIDBCreateCommandCreateCommand;
}
this.DangerousIDBCreateCommandCreateCommand = dangerousIDBCreateCommandCreateCommand;
}
internal OleDbHResult CreateCommand(ref object icommandText)
{
OleDbHResult result = OleDbHResult.E_NOINTERFACE;
UnsafeNativeMethods.IDBCreateCommandCreateCommand dangerousIDBCreateCommandCreateCommand = this.DangerousIDBCreateCommandCreateCommand;
if (dangerousIDBCreateCommandCreateCommand != null)
{
bool success = false;
RuntimeHelpers.PrepareConstrainedRegions();
try
{
base.DangerousAddRef(ref success);
result = dangerousIDBCreateCommandCreateCommand(base.handle, IntPtr.Zero, ref ODB.IID_ICommandText, ref icommandText);
}
finally
{
if (success)
{
base.DangerousRelease();
}
}
}
return(result);
}
internal void VerifyIDBCreateCommand(OleDbConnectionString constr) {
// DangerousAddRef/DangerousRelease are not neccessary here in the current implementation
// only used from within OleDbConnectionInternal.ctor->DataSourceWrapper.InitializeAndCreateSession
Debug.Assert(constr.HaveQueriedForCreateCommand, "expected HaveQueriedForCreateCommand");
Debug.Assert(null != constr.DangerousIDBCreateCommandCreateCommand, "expected DangerousIDBCreateCommandCreateCommand");
// native COM rules are the QI result is the 'this' pointer
// the pointer stored at that location is the vtable
// since IDBCreateCommand is a public,shipped COM interface, its layout will not change (ever)
IntPtr vtable = Marshal.ReadIntPtr(base.handle, 0);
IntPtr method = Marshal.ReadIntPtr(vtable, 3 * IntPtr.Size);
// obtain the cached delegate to be cached on this instance
UnsafeNativeMethods.IDBCreateCommandCreateCommand CreateCommand = constr.DangerousIDBCreateCommandCreateCommand;
// since the delegate lifetime is longer than the original instance used to create it
// we double check before each usage to verify the delegates function pointer
if ((null == CreateCommand) || (method != Marshal.GetFunctionPointerForDelegate(CreateCommand))) {
CreateCommand = (UnsafeNativeMethods.IDBCreateCommandCreateCommand)Marshal.GetDelegateForFunctionPointer(method, typeof(UnsafeNativeMethods.IDBCreateCommandCreateCommand));
constr.DangerousIDBCreateCommandCreateCommand = CreateCommand;
}
// since this instance can be used to create multiple commands
// cache it on the class so that the function pointer doesn't have to be validated every time
DangerousIDBCreateCommandCreateCommand = CreateCommand;
}
// if OleDbConnectionString.DangerousIDBCreateCommandCreateCommand does not exist
// this method will be called to query for IDBCreateCommand (and cache that interface pointer)
// or it will be known that IDBCreateCommand is not supported
internal void QueryInterfaceIDBCreateCommand(OleDbConnectionString constr) {
// DangerousAddRef/DangerousRelease are not neccessary here in the current implementation
// only used from within OleDbConnectionInternal.ctor->DataSourceWrapper.InitializeAndCreateSession
// caching the fact if we have queried for IDBCreateCommand or not
// the command object is not supported by all providers, they would use IOpenRowset
// SQLBU:446413, SQLHotfix:1138 -- added extra if condition
// If constr.HaveQueriedForCreateCommand is false, this is the first time through this method and we need to set up the cache for sure.
// If two threads try to set the cache at the same time, everything should be okay. There can be multiple delegates that point to the same unmanaged function.
// If constr.HaveQueriedForCreateCommand is true, we have already tried to query for IDBCreateCommand on a previous call to this method, but based on that alone,
// we don't know if another thread set the flag, or if the provider really doesn't support commands.
// If constr.HaveQueriedForCreateCommand is true and constr.DangerousIDBCreateCommandCreateCommand is not null, that means that another thread has set it after we
// determined we needed to call QueryInterfaceIDBCreateCommand -- otherwise we would have called VerifyIDBCreateCommand instead
// In that case, we still need to set our local DangerousIDBCreateCommandCreateCommand, so we want to go through the if block even though the cache has been set on constr already
if (!constr.HaveQueriedForCreateCommand || (null != constr.DangerousIDBCreateCommandCreateCommand)) {
IntPtr idbCreateCommand = IntPtr.Zero;
RuntimeHelpers.PrepareConstrainedRegions();
try {
// native COM rules are the QI result is the 'this' pointer
// the pointer stored at that location is the vtable
// since IUnknown is a public,shipped COM interface, its layout will not change (ever)
IntPtr vtable = Marshal.ReadIntPtr(base.handle, 0);
IntPtr method = Marshal.ReadIntPtr(vtable, 0);
UnsafeNativeMethods.IUnknownQueryInterface QueryInterface = (UnsafeNativeMethods.IUnknownQueryInterface)Marshal.GetDelegateForFunctionPointer(method, typeof(UnsafeNativeMethods.IUnknownQueryInterface));
int hresult = QueryInterface(base.handle, ref ODB.IID_IDBCreateCommand, ref idbCreateCommand); //
if ((0 <= hresult) && (IntPtr.Zero != idbCreateCommand)) {
vtable = Marshal.ReadIntPtr(idbCreateCommand, 0);
method = Marshal.ReadIntPtr(vtable, 3 * IntPtr.Size);
DangerousIDBCreateCommandCreateCommand = (UnsafeNativeMethods.IDBCreateCommandCreateCommand)Marshal.GetDelegateForFunctionPointer(method, typeof(UnsafeNativeMethods.IDBCreateCommandCreateCommand));
constr.DangerousIDBCreateCommandCreateCommand = DangerousIDBCreateCommandCreateCommand;
}
// caching the fact that we have queried for IDBCreateCommand
constr.HaveQueriedForCreateCommand = true;
}
finally {
if (IntPtr.Zero != idbCreateCommand) {
IntPtr ptr = base.handle;
base.handle = idbCreateCommand;
Marshal.Release(ptr);
}
}
}
//else if constr.HaveQueriedForCreateCommand is true and constr.DangerousIDBCreateCommandCreateCommand is still null, it means that this provider doesn't support commands
}
internal void VerifyIDBCreateCommand(OleDbConnectionString constr)
{
IntPtr ptr = Marshal.ReadIntPtr(Marshal.ReadIntPtr(base.handle, 0), 3 * IntPtr.Size);
UnsafeNativeMethods.IDBCreateCommandCreateCommand dangerousIDBCreateCommandCreateCommand = constr.DangerousIDBCreateCommandCreateCommand;
if ((dangerousIDBCreateCommandCreateCommand == null) || (ptr != Marshal.GetFunctionPointerForDelegate(dangerousIDBCreateCommandCreateCommand)))
{
dangerousIDBCreateCommandCreateCommand = (UnsafeNativeMethods.IDBCreateCommandCreateCommand) Marshal.GetDelegateForFunctionPointer(ptr, typeof(UnsafeNativeMethods.IDBCreateCommandCreateCommand));
constr.DangerousIDBCreateCommandCreateCommand = dangerousIDBCreateCommandCreateCommand;
}
this.DangerousIDBCreateCommandCreateCommand = dangerousIDBCreateCommandCreateCommand;
}
